/*
 * Licensed to ObjectStyle LLC under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ObjectStyle LLC licenses
 * this file to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

package io.bootique;

import com.google.inject.Binder;
import com.google.inject.Module;
import io.bootique.names.ClassToName;

import java.util.Objects;

/**
 * A Bootique-specific Guice Module that sets up a one or another application
 * subsystem. It is intended as a superclass for Modules that are centered
 * around a single YAML configuration, so it is used in Bootique integration
 * modules, etc.
 * 
 * @since 0.9
 */
public abstract class ConfigModule implements Module {

	protected static ClassToName CONFIG_PREFIX_BUILDER = ClassToName
			.builder()
			.convertToLowerCase()
			.stripSuffix("Module")
			.build();

	protected String configPrefix;

	public ConfigModule() {
		init(defaultConfigPrefix());
	}

	public ConfigModule(String configPrefix) {
		init(configPrefix);
	}

	private void init(String configPrefix) {
		Objects.requireNonNull(configPrefix);
		this.configPrefix = configPrefix;
	}

	/**
	 * Does nothing and is intended for optional overriding.
	 */
	@Override
	public void configure(Binder binder) {
		// do nothing
	}

	protected String defaultConfigPrefix() {
		return CONFIG_PREFIX_BUILDER.toName(getClass());
	}

}
